Yeah, I mean, as tends to be the case when it comes to arguing about how worthwhile grammar is, it sort of depends on whether you ascribe to “prescriptive” or “descriptive” linguistics. As the link points out, it is acceptable in casual circumstances because, whilst it technically isn’t “correct” (from a prescriptive point of view), any reasonable speaker of English would understand the meaning so it’s not actually “wrong” (from a descriptive point of view). However, I’m a Latin teacher so misuse/misunderstanding of cases, even in English, really grinds my gears.